A motorcyclist from Anne Arundel County remained in critical condition at a hospital Friday morning, authorities report, the day after his motorcycle struck a horse pulling a buggy across Route 6 in New Market.

Donald Lee Fridell Jr., 52, of Lothian and another motorcyclist were traveling west on the highway at about 3:43 p.m. Thursday, St. Mary’s sheriff’s deputies report, when the horse and buggy operated by 48-year-old Luna Hertzler Fisher of Mechanicsville turned left from the westbound shoulder to cross both lanes of the highway.

Fridell’s Harley Davidson struck the horse, and Fridell was thrown from the motorcycle before he and the motorcycle both landed in an eastbound shoulder ditch, according to the sheriff’s office. Fridell was unconscious when police arrived.

The other motorcyclist, Lawrence Francis Jones of Lothian, lost control of his motorcycle as he locked its rear brake, and he was ejected as it went to the ground, according to a release from the preliminary investigation by sheriff’s Cpl. Brian Connelly. Jones was taken by an ambulance crew to the University of Maryland Charles Regional Medical Center to be treated for non-life threatening injuries.

A Maryland State Police helicopter crew flew Fridell to the University of Maryland Hospital’s shock-trauma center in Baltimore.

No injuries to the buggy’s operator were reported. The injured horse was shot and killed at the scene.

The sheriff’s office has requested that anyone with information about the accident call the agency at 301-455-4200, ext. 9010.